Microelectronic devices, such as semiconductor devices and field emission displays, are generally fabricated on and/or in microelectronic workpieces using several different types of machines (“tools”). Many such processing machines have a single processing station that performs one or more procedures on the workpieces. An example of one such tool is a single-chamber Equinox tool available from Semitool, Inc. of Kalispell, Mont. This tool can have a shelf on which a container of microelectronic workpieces is positioned, and a single processing chamber for electrochemically processing the workpieces. A user can manually load the workpieces one by one into the chamber, for example, to test or demonstrate processing recipes or other processing parameters.
While the foregoing tool is useful in the engineering environment, production level processing requires greater throughput than can be provided by a single-chamber tool. Accordingly, other processing machines have a plurality of processing stations that can perform a series of different procedures on individual workpieces or batches of workpieces. For example, the LT210C and Spectrum tools, also available from Semitool, Inc., provide automated processing in a batch and single-wafer environment, respectively. These tools include robots that automatically remove the microelectronic workpieces from a container, move the microelectronic workpieces among the relevant processing stations, and return the microelectronic workpieces to the container after processing. While such tools are very effective for processing large volumes of microelectronic workpieces, they may not be cost-effective or practical when used in an engineering, test or demonstration environment.
One problem with the foregoing tools is that they typically require a clean room environment in which to operate. Clean rooms are expensive to build and maintain, and accordingly tool manufacturers attempt to maximize the number of microelectronic workpieces processed per hour per square foot of clean room area occupied by the tool. However, despite efforts to make tools as compact and efficient as possible, there is continual pressure to reduce the size of the tool (e.g. the “footprint” of the tool) and increase the efficiency of the tool. This pressure becomes all the more intense when device manufacturers require both engineering/test and production processing capabilities, which in turn requires even more clean room area.